Treatment of textiles



Patented .luly 19, 1932 UNITED STATES P ATENT: oFFIcE GEORGE HOLLAND ELLIS, OF SPONDON, NEAR DERBY, ENGLAND, ASSIGNOB. TO CELAN- ESE CORPORATION OF AMERICA, A CORPORATION OF DELAWARE TREATMENT TEXTILES No Drawing. Application filed March 10, 1928, Serial No. 260,820, and in Great Britain November 15, 1927.

This invention relates to the degumming of natural silk in yarn, fabric or other form and provides a process which is particularly applicable to the treatment of yarns, fabrics or other goods containing natural silk mixed or associated with yarns, fibres or filaments of cellulose esters and more especially cellulose acetate.

The process may, however, be applied with advantage to the treatment of yarns, fabrics or other goods consisting wholly of natural silk or consisting of natural silk associated or mixed with other fibres, for example, cotton, linen, wool or artificial silks of the cellulose tYPe- Acc'ordmg to the present inventlon goods made of or containing natural silk and particularly goods made of natural silk and cellulose acetate or other cellulose ester artificial silk are treated for the purpose of removing the gum from the silk with an alkaline liquor having a pH value not exceeding 10.5 or whose pH value has been adjusted so as not to exceed 10.5. In other words the hydrogen ion concentration must be at least 10 .(i. e.

grams per litre.

It has been found that a liquor having that degree of alkalinity successfully removes the sericin from the silk and at the same time has no deleterious eflect upon the fibroin of the silk or upon any cellulose ester fibres which may be present in association with the silk.

Preferably the alkalinity of the degum-.

ming reagent used has oris adjusted to an initial value of pH 10 to pH 10.5 and furthermore is preferably maintained within this range during the degumming operation by further additions of alkali as they become necessary.

Any suitable alkalies may be employed for the purpose of the present invention, those we find especially useful being soluble organic or inorganic salts of the alkalies, for example silicates, borates, carbonates, phenolates, and cresolates of lithium, sodium or potassium. Hydroxides, for instance causticsoda or potash, may also be used, Preferably we use baths containing soaps or sulphonated soaps or oils. In all cases the value if not pH value Phenol violet indicates between 8. 0 and 10.0 Phenol thymol phthalein indicates between 8. 3 and 11. 0 Thymol pllthalein indicates between 9.3 and 10. 5

Universal" Indicator (British Drug Houses) (a mixture of indicators showing a number of difierent colours throughout the range) indicates between 3.0 and I1. 0

In degumming mixtures comprising natural silk and cellulose acetate, the conditions and more particularly the temperature may be so adjusted as to delustre the cellulose acetate wholly or partially. Temperatures above 80 C. will usually effect this delustering.

The process of the present invention may be carried out by any suitable manipulative method using liquid or foam baths, the duration and temperature of the treatment being varied according to the method used, the class of goods treated, etc.

The following examples illustrate the processes of the present invention but are not to w be regarded as in any way limitative:

Example 1 To degum a fabric made up of natural silk and cellulose acetate components in the ratios of 1:2 by weight, a bath is made up of soft water containing 5 The volume used should be calculated so that the ratio to the weight of goods is about 60: 1. If necessary the pH value is adjusted to the figure of 1010.5 by addition of sodium phenate. The bath is adjusted to a temperature of about 80 C. and the goods entered and treated for 3-4 hours with maintenance of the temperature at 80 C. and pH value at the above figure by cautious additions of sodium phenate solution. The goods are now best finally cleared of mechanically adhering particles by a further light soaping for 1 hour at 80 C. in a bath containing about 2 grams per litre of neutral soap. The goods are then rinsed and dried or otherwise treated as requisite.

Owing to this maintenance ofthe degumgrams per litre of soap.

ming bath at the pH value mentioned, the same bath may be used repeatedly.

Example 2 To degum fabric made up of equal parts by weight of natural silk and cellulose acetate so that the goods have a so-called matt ap; pearance or less bright appearance than normal owing to decrease of the lustre of the cellulose acetate, a bath is made up of soft water containing 5 grams per litre of soap and the volume is adjusted to the amount of goodsto be treated exactly as in Example 1.

If necessary the pH value is adjusted to about 10.0 by addition of caustic soda solution. The fabric is entered into the bath at 95 C. and the treatment carried on for 3-4 hours at this temperature, the bath being maintained at the above pH figure by cautious additions of caustic soda solution. As in Example 1 a light soaping is usually advisable following which the goods may be rinsed, dried. and treated as requisite.

As in Example 1 the bath may be used repeatedly.

The above figures for pH are based upon determinations at around 25 C. Therefore, in adjusting and testing the baths the samples taken should be cooled to about this temperature.

If desired, dyeing may be carried out simultaneously with the degumming, appropriate dyestuifs being chosen for the silk and/or for the fibresassociated therewith, if any.

lrVhat I claim and desire to secure by Letters Patent is 1. Process for degumming materials comprising natural silk, comprising treating the materials with an alkaline liquor having a hydrogen ion concentration of a between 10' and 10* grams per litre.

2. Process for degumming materials comprising natural silk, comprising treating the materials with an alkaline liquor having an initial hydrogen ion concentration of between 10* and 10* grams per litre and maintaining the concentration between these values throughout the treatment by additions of alkali.

3. Process for degumming and dyeing materials comprising natural silk, comprising treating the materials in an alkaline liquor containing at least one dyestuif and having a hydrogen ion concentration of between 10 and 10* grams per litre.

4. Process for degumming materials comprising natural silk and cellulose acetate, comprising treating the materials with an alkaline liquor having a hydrogen ion concentration of at least l0- grams per litre.

5. Process for degumming materials comprising natural silk and cellulose acetate, comprising treating the materials with an alkaline liquor containinga soap having a asszceo hydrogen ion concentration of at least 10 grams per litre.

6. Process for degumming materials comprising natural silk and cellulose acetate, comprising treating the materials with an alkaline liquor having hydrogen ion concentration of between 10*- and l0' grams per litre.

7. Process for degumming materials comprising natural silk and cellulose acetate, comprising treating the materials with an alkaline liquor having an initial hydrogen ion concentration of between 10- and 10 grams per litre and maintaining the concentration between these values throughout the treatment by additions of alkali.

8. Process for degumming and dyeing materials comprising'natural silk and cellulose acetate, comprising treating the materials in an alkaline liquor containing at least one dyestuif and having a hydrogen ion concentration of at least 10- grams per litre.

9. Process for degumming the silk and delustering the cellulose acetate of materials comprising natural silk and cellulose acetate, comprising treating the materials at a suificiently elevated temperature to cause the delustering with an alkaline liquor having a hydrogen ion concentration of at least 10 grams per litre.

In testimony whereof I have hereunto subscribed my name.

GEORGE HOLLAND ELLIS. 

